Merge develop into ops to create gefs.v12.3.9-0 tag

[EricSinsky-NOAA]

This PR intends to merge the following changes from GEFS/dev to GEFS/ops:

• Update gw tag to gefs_v12.3.9 in sorc/checkout.sh to address a script change in GSL-prep-chem that allows GBBEPX v5 data to be used instead of v4 (GSL-prep_chem issue #12)
• Update MAIL_LIST in versions/run.ver
• Update gefs_ver to v12.3.9 in versions/run.ver
• Update w3emc_ver from 2.7.3 to 2.9.2 in versions/build.ver to fix module loading issue in GSI build

[EricSinsky-NOAA]

gefs.v12.3.9-0 tag has been created.